To find out which customers owe you money you will need to check the debtors report.
Go to Reporting in the top right corner. (if you don't see this link it is because you don't have permission to view the reports in CommuSoft, please speak to your system administrator/boss/business owner who can change the level of access you have to CommuSoft. Note: CommuSoft's support staff cannot do this for you).
Click on Your Business > Debtors/Credits > Debtors Report.
This report will show you a list of every customer who owes you money. To drill down to view the individual invoices, click on the customers name.